This invention relates to rotary cutters or routers that are used to trim or cut metal protrusions from aircraft airframe parts such as wing elements, panels and the like. The new router apparatus allows one operator to secure the apparatus in position for trimming and to perform the trimming without assistance of others.
Rotary cutters or hand held routers are currently used to trim or cut protruding metal from the surface and edges of aircraft structural elements. Tabs, rivets and the like often protrude or extend above what is intended to be a finish surface or edge after assembly of aircraft metal structural elements. A hand held router with a rotary burr cutter tool is often used to trim any such irregular metal protrusions. The problem with hand use is that an uneven finishing may be caused by the difficulty in holding the router due to torsional forces created in trimming. Also, a second person may be required to vacuum dust created during the trimming operation.
Currently used methods for trimming tabs from aircraft panel edges use a router fence guide that is clamped onto a wing metal skin at an edge using removable index pins for positioning. An air motor router with a nose bushing resting on the router fence guide is moved along the wing edge to trim protruding tabs. A second operator positions a vacuum dust collection hose during the trimming to collect cuttings. This method is noisy due partially to the rotary file burr cutter tool spring back against the force of the operator caused by the torsional forces created. Also, the cutting tool vibrates, bounces and chatters creating an uneven finish and causing early cutting tool failure.
The problems created when a rotary cutter or router supports only one end of a cutting tool have been addressed in design of cutting machines. In cases where significant force may be created by the cutting or trimming operation both ends of the cutting tool may be supported to reduce spring back or bouncing of an unsupported cutting tool end. An example of such an apparatus is disclosed in U.S. Pat. No. 4,033,230. In this instance the cutter is supported at both ends by an upper and lower collet or chuck. This particular solution does not lend itself to the small hand held rotary cutter, which must be portable and easily positioned at the work site.
As can be seen, there is a need for a simple, portable router apparatus that is controlled in movement by a cutting guide apparatus and that has a supported cutting tool.
An improved aircraft panel detab router according to the present invention comprises a tool fixture for clamping to an airframe metal skin edge, a router with cutting tool movably attached to the tool fixture and a vacuum manifold debris collection assembly.
In one aspect of the present invention a panel detab router comprises a tool fixture having a linear slide and a plurality of edge guide pin locators for positioning on a metal panel edge. A clamping mechanism is attached to the tool fixture to retain it on the metal panel. A sliding assembly having a router with a cutter tool is slidably engaged with the linear slide for movement parallel to the metal panel edge with the cutter tool along the edge thereof. A support arm is attached to the sliding assembly extending parallel with the cutter tool and having a tool bearing therein for engagement with a distal end of the cutter tool.
In another aspect of the invention the router is attached to an adjustable eccentric cam ring mount for mounting and vertical positioning of the router for cutting. The cam ring mount may be releasably locked by a cam lever.
In yet another aspect of the invention the clamping mechanism comprises a clamp arm attached to a clamp rod and the clamp rod is slidably engaged with a clamp trigger retract mechanism having a release trigger. The clamp trigger retract mechanism is attached to a clamp support mount. The clamp support rod has a clamp return spring thereon which is positioned between the clamp arm and the clamp support mount. When the release trigger is activated the clamp return spring applies force to disengage the clamp arm. The clamp support mount is attached to the tool fixture. Also a vacuum manifold is attached to the sliding assembly to collect debris from the trimming.
In a further aspect of the present invention a method for trimming protruding tabs from panel edges involves the steps of positioning the tool fixture at a panel edge and clamping it thereto, adjusting the eccentric cam ring mount of the sliding assembly to position the router and cutter tool; powering the router and sliding the sliding assembly along the linear slide of the tool fixture to trim protruding tabs; and vacuuming debris produced by the trimming.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.